In a wireless communications system having a feature of carrier aggregation (Carrier Aggregation, CA for short), a user equipment may communicate with a base station through multiple cells. Generally speaking, in the prior art, a user equipment may execute random access through a primary cell to achieve uplink synchronization. However, transmission paths through which an uplink signal of the user equipment is sent to the base station through different cells may be different, for example, an uplink signal sent by the user equipment to the base station through some cells may need to pass through a relay node, but an uplink signal sent to the base station through other cells may not need to pass through a relay node, so that the user equipment cannot achieve uplink synchronization by executing random access only through a primary cell, and random access further needs to be executed through a secondary cell to achieve uplink synchronization.
However, it is not provided in the prior art that how a user equipment determines an uplink transmission power of the user equipment when random access is executed through a secondary cell.